The focus of this 36-month study is on the role of social networks on the development and maintenance of drinking careers. The proposed project aims to identify drinking phases throughout the drinking career of 50 subjects who have been diagnosed with alcoholism or alcohol abuse and 50 subjects who are considered social drinkers. Of particular interest in this project is the change process when individuals leave one drinking phase to enter another. Therefore, the project will focus on factors contributing to this change process, and particularly study the role of the social networks herein. The project will use experiences from already existing tools, like the Timeline Follow Back, Lifetime Drinking History, the Cognitive Lifetime Drinking History, and the Adult Life Phase History that have been developed to study drinking retrospectively, in combination with a qualitative interview methodology to investigate drinking careers. This combination of structured and semi-structured instruments will secure the most accurate and reliable data from the respondents. It is expected that the project will generate new knowledge that will shed more light on the relationship between individual drinking behavior and social networks, e.g., the direction of the relationship, that is, do social networks influence individual drinking behavior, or do drinkers actively choose social networks that share the same values and/or drinking habits as themselves? Furthermore, it is expected that the project will generate information on the complicated interrelatedness between life events, social networks, and individual drinking behavior. This information will be valuable in developing new individually-based preventive measures. Knowing about the impact of the networks will enable us to develop programs that will incorporate the immediate social networks of people at risk for developing alcohol problems in the preventive work. Also, this information will provide an expanded basis for the treatment of alcohol problems. By providing information on the specifics about the role of social networks, this complicated relation can be drawn into treatment programs, and the influence of the environment can be targeted directly.